dfu/img_util: fix flash_sector_from_off

flash_sector_from_off fetched sector data of page
in relation to the flash memory beginning instead of the flash
area beginning.
Issue was invisible as on most devices all sectors looks similar.

Signed-off-by: Andrzej Puzdrowski <[email protected]>

Author: nvlsianpu

subsys/dfu/img_util/flash_img.c

@@ -75,6 +75,9 @@ static int flash_sector_from_off(struct flash_area const *fap, off_t off,
 	int rc = -ENODEV;
 
 	flash_dev = flash_area_get_device(fap);
+
+	off += fap->fa_off; /* flash driver uses offset from memory beginning */
+
 	if (flash_dev) {
 		rc = flash_get_page_info_by_offs(flash_dev, off, &page);
 		if (rc == 0) {
@@ -110,7 +113,9 @@ static int flash_progressive_erase(struct flash_img_context *ctx, off_t off)
 			ctx->off_last = sector.fs_off;
 			LOG_INF("Erasing sector at offset 0x%08lx",
 				(long)sector.fs_off);
-			rc = flash_area_erase(ctx->flash_area, sector.fs_off,
+			rc = flash_area_erase(ctx->flash_area,
+					      sector.fs_off -
+					      ctx->flash_area->fa_off,
 					      sector.fs_size);
 			if (rc) {
 				LOG_ERR("Error %d while erasing sector", rc);